AOC LM-522 User manual

LM-522 Service Manual
1
SERVICE MANUAL
15” LCD Monitor
LM-522
THESE DOCUMENTS ARE FOR REPAIR SERVICE INFORMATION ONLY. EVERY REASONABLE EFFORT
HAS BEEN MADE TO ENSURE THE ACCURACY OF THIS MANUAL; WE CANNOT GUARANTEE THE ACCURACY
OF THIS INFORMATION AFTER THE DATE OF PUBLICATION AND DISCLAIMS RELIABILITY FOR CHANGES,
ERRORS OR OMISSIONS.

LM-522 Service Manual
2
CONTENT TABLE
1.MONITOR SPECIFICATIONS ......................................................................................................4
2. LCD MONITOR DESCRIPTION ..................................................................................................4
3. OPERATING INSTRUCTIONS....................................................................................................5
3.1 GENERAL INSTRUCTIONS...................................................................................................5
3.2 CONTROL BUTTONS............................................................................................................5
3.3 ADJUSTING THE PICTURE...................................................................................................5
4. INPUT/ OUTPUT SPECIFICATION.............................................................................................7
4.1 INPUT SIGNAL CONNECTO..........................................................................................................7
4.2 FACTORY PRESET DISPLAY MODES ............................................................................................7
4.3 POWER SUPPLY REQUIREMENTS................................................................................................8
4.4 PANEL SPECIFICATION........................................................................................................8
4.4.1 Panel Feature.....................................................................................................................8
4.4.2 Display Characteristics........................................................................................................9
4.4.3 Optical Characteristics.........................................................................................................9
4.4.4 Parameter guideline for CCFL Inverter................................................................................10
4.4.5 Back-light Unite.................................................................................................................10
5. BLOCK DIAGRAM.................................................................................................................... 11
5.1 MONITOR EXPLODED VIEW ...................................................................................................... 11
5.2 SOFTWARE FLOWING CHART ...................................................................................................12
5.3 ELECTRICAL BLOCK DIAGRAM ..................................................................................................14
5.3.1 Main Board.......................................................................................................................14
5.3.2 Inverter/Power Board.........................................................................................................14
6. SCHEMATIC..............................................................................................................................16
6.1 MAIN BOARD ..........................................................................................................................16
6.2 POWER BOARD .......................................................................................................................21
7. PCB LAYOUT............................................................................................................................23
7.1 MAIN BOARD ..........................................................................................................................23
7.2POWER BOARD ........................................................................................................................24
7.3 KEYPAD BOARD ......................................................................................................................25
8. MAINTAINABILITY....................................................................................................................26
8.1 REQUIREMENTS AND TOOLS REQUIREMENT ..............................................................................26
8.2 TROUBLE SHOOTING ...............................................................................................................27
8.2.1 MAIN BOARD........................................................................................................................27
8.2.2 Key Pad Board .................................................................................................................29
9. WHITE-BALANCE, LUMINANCE ADJUSTMENT....................................................................30

LM-522 Service Manual
3
10. EDIT CONTENT.......................................................................................................................31
11.BOM LIST.................................................................................................................................32

LM-522 Service Manual
4
1.MONITOR SPECIFICATIONS
• 38 cm (15”) a-si TFTActive matrix LCD panel, 0.297mm dot pitch.
• Microprocessor controlled scan technology
• 16 factory presets , 18 new modes
• Vertical refresh rate 55Hz to 75 Hz
• Horizontal frequency 30kHz to 60kHz
• Resolutions: 640 x 480 up to 1024 x 768
• Universal power supply designed for worldwide application
• CE mark
• TCO-99
• VESA DPMS compliant
• VESA DDC compliant
2. LCD MONITOR DESCRIPTION
The LCD MONITOR will contain a main board, a power board, a keypad board and an audio board which house the flat
panel control logic, brightness control logic and DDC.
The power board will provideAC to DC Inverter voltage to drive the backlight of panel and the main board chips each
voltage.
Video signal, DDC
CCFT Drive.
PWPC Board
(
Include Ada
p
ter and Inverter
)
Flat Panel and
CCFL
Main Board
Keyboard
RS232 Connector
For white balance
adjustment in factory
mode
HOST Computer
AC-IN
100V-240V
Monitor Block Diagram
Audio board

LM-522 Service Manual
5
3. OPERATING INSTRUCTIONS
3.1 GENERAL INSTRUCTIONS
Press the power button to turn the monitor on or off. The other control buttons are located in the front of the monitor. By
changing these settings, the picture can be adjusted to your personal preferences.
•The power cord should be connected.
•Connect the video cable from the monitor to the video card.
•Press the power button to turn on the monitor position. The power indicator will light up.
3.2 CONTROL BUTTONS
AUTO VOL- POWER VOL+ MENU
3.3 ADJUSTING THE PICTURE
NO. Name Within OSD Without OSD
1 Auto 1. Exit Sub menu
2. Exit the menu item
Run the Auto Adjust when this
button keep to push for 2 second
2 VOL - / 1.Move the cursor to down
2.Adjust down when menu item selected Open the Brightness menu
3 Power Turn on/off Turn on/off
4 VOL + / 1.Move the cursor to up
2.Adjust up when menu item selected Open the contrast menu
5 MENU 1.Enter the OSD sub menu
2.Select the OSD menu Open OSD menu

LM-522 Service Manual
6
The descriptions for function control LEDS
Main Menu
Item
Main
Menu Icon Sub Menu Item Sub Menu Icon Description
Contrast Contrast from Digital-register
Luminance Brightness Backlight Adjustment
Focus
Adjust Picture Phase to reduce Horizontal-Line
noise
Image Setup Clock Adjust picture Clock to reduce Vertical-Line noise.
H. Position Adjust the horizontal position of the picture.
Image Position V. Position Adjust the vertical position of the picture.
Warm N/A Recall Warm Color Temperature from EEPROM.
Cool N/A Recall Cool Color Temperature from EEPROM.
User / Red Red Gain from Digital-register.
User / Green Green Gain Digital-register.
Color Temp.
User / Blue Blue Gain from Digital-register.
Analog N/A Select input signal from analog source (D-Sub)Input Select
Digital N/A Select input signal from digital source (DVI)
H. Position Adjust the horizontal position of the OSD.
V. Position Adjust the vertical position of the OSD.
OSD Setup
OSD Timeout Adjust the OSD timeout.
English N/A Set OSD display language to English.
Deutsch N/A Set OSD display language to German.
Français N/A Set OSD display language to French.
Español N/A Set OSD display language to Spain.
Italiano N/A Set OSD display language to Italian.
Language
Simplified Chinese N/A Set OSD display language to Simplified Chinese.
Information Information N/A
Show the resolution, H/V frequency and input port
of current input timing.
Reset Yes N/A
Clear each old status ofAuto-configuration and set
the color temperature to Cool.

LM-522 Service Manual
7
No N/A Do not execute reset, return to main menu.
Exit N/A N/A Exit OSD
4. Input/ Output Specification
4.1 Input Signal Connector
1 Red Video 9 +5 v
2 Green Video 10 Logic Ground
3 Blue Video 11 RS-232 RX
4 RS-232 TX 12 DDC-Serial Data
5 DDC-Return 13 H-Sync.
6 Red Ground 14 V-Sync.
7 Green Ground 15 DDC-Serial Clock
8 Blue Ground
CONNECTOR PIN ASSIGNMENT
15
610
11 15
4.2 Factory Preset Display Modes
VESA MODES
Horizontal Vertical
Mode Resolution Total
Nominal
Frequency
+/- 0.5kHz
Sync
Polarity
Nominal
Freq.
+/- 1 Hz
Sync
Polarity
Nominal
Pixel
Clock
(MHz)
640x480@60Hz 800 x 525 31.469 N 59.940 N 25.175
640x480@72Hz 832 x 520 37.861 N 72.809 N 31.500
VGA
640x480@75Hz 840 x 500 37.500 N 75.00 N 31.500
800x600@56Hz 1024 x 625 35.156 N/P 56.250 N/P 36.000
800x600@60Hz 1056 x 628 37.879 P 60.317 P 40.000
800x600@72Hz 1040 x 666 48.077 P 72.188 P 50.000
SVGA
800x600@75Hz 1056x625 46.875 P 75.000 P 49.500
1024x768@60Hz 1344x806 48.363 N 60.004 N 65.000
1024x768@70Hz 1328x806 56.476 N 70.069 N 75.000
XGA
1024x768@75Hz 1312x800 60.023 P 75.029 P 78.750
IBM MODES
Horizontal Vertical

LM-522 Service Manual
8
Mode Resolution Total
Nominal
Frequency
+/- 0.5kHz
Sync
Polarity
Nominal
Freq.
+/- 1 Hz
Sync
Polarity
Nominal
Pixel
Clock
(MHz)
DOS 720x400@70Hz 900 x 449 31.469 N 70.087 P 28.322
DOS 640x350@70Hz 800 x 449 31.469 P 70.087 N 25.175
XGA 1024x768@72Hz 1304x798 57.515 P 72.100 P 75.000
MAC MODES
VGA
640x480@67Hz 864x525 35.000 N 66.667 N 30.240
SVGA
832x624@75Hz 1152x667 49.725 N 74.551 N 57.2832
XGA 1024x768@75Hz 1328x804 60.241 N 74.927 N 80.000
4.3 Power Supply Requirements
A/C Line voltage range : 100 V ~ 240 V
A/C Line frequency range : 50 ±3Hz, 60 ±3Hz
Current : 0.6A max. at 100V , 0.35A max. at 240 V <0.3A
Peak surge current : < 55A peak at 240 VAC and cold starting
Leakage current : < 3.5mA
Power line surge : No advance effects (no loss of information or defect)
with a maximum of 1 half-wave missing per second
Voltage : 12VDC ± 5 %
Current : 3.5max
4.4 PANEL SPECIFICATION
4.4.1 Panel Feature

LM-522 Service Manual
9
4.4.2 Display Characteristics
4.4.3 Optical Characteristics

LM-522 Service Manual
10
4.4.4 Parameter guideline for CCFL Inverter
4.4.5 Back-light Unite

LM-522 Service Manual
11
5. Block Diagram
5.1 Monitor Exploded View

LM-522 Service Manual
12
5.2 Software Flowing Chart
1
2
N
Y
5
Y
N
10
Y
N
12
Y
N
7
Y
N
6
4
3
8
9
14
11
13
Y
N
15
Y
N16
17
19
Y
N
18

LM-522 Service Manual
13
1) MCU initialize
2) Is the EPROM blank?
3) Program the EPROM by default values.
4) Get the PWM value of brightness from EPROM.
5) Is the power key pressed?
6) Clear all global flags.
7) Are theAUTO and SELECT keys pressed?
8) Enter factory mode.
9) Save the power key status into EPROM. Turn on the LED and set it to green color.
Scaler initialize.
10) In standby mode?
11) Update the lifetime of back light.
12) Check the analog port, are there any signals coming?
13) Does the scalar send out an interrupt request?
14) Wake up the scalar.
15) Are there any signals coming from analog port?
16) Display "No connection Check Signal Cable" message. And go into standby mode after the message
disappears.
17) Program the scalar to be able to show the coming mode.
18) Process the OSD display.
19) Read the keyboard. Is the power key pressed?

LM-522 Service Manual
14
5.3 Electrical Block Diagram
5.3.1 Main Board
5.3.2 Inverter/Power Board
Buck Connector Parallet-resonant
Driver Dimming control
(· §² ¤¹ Ï )
Parallet-resonant
inverter
CCFL
PWM
Dimming control
Driver
Circuit
Vin
Vin inverter
(PW M )
Circuit
Inverter Block Diagram

LM-522 Service Manual
15
Power Block Diagram

LM-522 Service Manual
16
6. Schematic
6.1 Main Board

LM-522 Service Manual
17

LM-522 Service Manual
18

LM-522 Service Manual
19

LM-522 Service Manual
20